from selenium import webdriver

driver = webdriver.Chrome()

driver.get(' http://cdn1.python3.vip/files/selenium/test2.html')
# 选择已经选中的老师
element = driver.find_element_by_css_selector('div#s_radio input[checked="checked"]')
# 将选中的老师打印出来
print(element.get_attribute('value'))

# 重新选择老师
click_teacher = driver.find_element_by_css_selector('div#s_radio input[value="小雷老师"]').click()